scholarly journals Nfatc1’s Role in Mammary Epithelial Morphogenesis and Basal Stem/progenitor Cell Self-renewal

Author(s):  
Melissa McNeil ◽  
Yingying Han ◽  
Peng Sun ◽  
Kazuhide Watanabe ◽  
Jun Jiang ◽  
...  

AbstractMammary gland is an outstanding system to study the regulatory mechanisms governing adult epithelial stem cell activity. Stem cells in the basal layer of the mammary gland fuel the morphogenesis and regeneration of a complex epithelial network during development and upon transplantation. The self-renewal of basal stem/progenitor cells is subjected to regulation by both cell-intrinsic and extrinsic mechanisms. Nfatc1 is a transcription factor that regulates breast tumorigenesis and metastasis, but its role in mammary epithelial development and stem cell function has not been investigated. Here we show that Nfatc1 is expressed in a small subset of mammary basal epithelial cells and its epithelial-specific deletion results in mild defects in side branching and basal-luminal cell balance. Moreover, Nfatc1-deficient basal cells exhibit reduced colony forming ability in vitro and somewhat compromised regenerative potential upon transplantation. Thus, our study provides evidence for a detectable yet non-essential role of Nfatc1 in mammary epithelial morphogenesis and basal stem/progenitor cell self-renewal.

Development ◽  
1998 ◽  
Vol 125 (10) ◽  
pp. 1921-1930 ◽  
Author(s):  
E.C. Kordon ◽  
G.H. Smith

Any epithelial portion of a normal mouse mammary gland can reproduce an entire functional gland when transplanted into an epithelium-free mammary fat pad. Mouse mammary hyperplasias and tumors are clonal dominant populations and probably represent the progeny of a single transformed cell. Our study provides evidence that single multipotent stem cells positioned throughout the mature fully developed mammary gland have the capacity to produce sufficient differentiated progeny to recapitulate an entire functional gland. Our evidence also demonstrates that these stem cells are self-renewing and are found with undiminished capacities in the newly regenerated gland. We have taken advantage of an experimental model where mouse mammary tumor virus infects mammary epithelial cells and inserts a deoxyribonucleic acid copy(ies) of its genome during replication. The insertions occur randomly within the somatic genome. CzechII mice have no endogenous nucleic acid sequence homology with mouse mammary tumor virus; therefore all viral insertions may be detected by Southern analysis provided a sufficient number of cells contain a specific insertional event. Transplantation of random fragments of infected CzechII mammary gland produced clonal-dominant epithelial populations in epithelium-free mammary fat pads. Serial transplantation of pieces of the clonally derived outgrowths produced second generation glands possessing the same viral insertion sites providing evidence for self-renewal of the original stem cell. Limiting dilution studies with cell cultures derived from third generation clonal outgrowths demonstrated that three multipotent but distinct mammary epithelial progenitors were present in clonally derived mammary epithelial populations. Estimation of the potential number of multipotent epithelial cells that may be evolved from an individual mammary-specific stem cell by self-renewal is in the order of 10(12)-10(13). Therefore, one stem cell might easily account for the renewal of mammary epithelium over several transplant generations.


2012 ◽  
Vol 2 (1) ◽  
pp. 11-21
Author(s):  
Silvia Cristini ◽  
Giulio Alessandri ◽  
Francesco Acerbi ◽  
Daniela Tavian ◽  
Eugenio A. Parati ◽  
...  

2012 ◽  
Vol 2 (1) ◽  
pp. 11-21
Author(s):  
Silvia Cristini ◽  
Giulio Alessandri ◽  
Francesco Acerbi ◽  
Daniela Tavian ◽  
Eugenio A. Parati ◽  
...  

2021 ◽  
Vol 22 (2) ◽  
pp. 666
Author(s):  
Toshio Takahashi

Stem cells have extensive proliferative potential and the ability to differentiate into one or more mature cell types. The mechanisms by which stem cells accomplish self-renewal provide fundamental insight into the origin and design of multicellular organisms. These pathways allow the repair of damage and extend organismal life beyond that of component cells, and they probably preceded the evolution of complex metazoans. Understanding the true nature of stem cells can only come from discovering how they are regulated. The concept that stem cells are controlled by particular microenvironments, also known as niches, has been widely accepted. Technical advances now allow characterization of the zones that maintain and control stem cell activity in several organs, including the brain, skin, and gut. Cholinergic neurons release acetylcholine (ACh) that mediates chemical transmission via ACh receptors such as nicotinic and muscarinic receptors. Although the cholinergic system is composed of organized nerve cells, the system is also involved in mammalian non-neuronal cells, including stem cells, embryonic stem cells, epithelial cells, and endothelial cells. Thus, cholinergic signaling plays a pivotal role in controlling their behaviors. Studies regarding this signal are beginning to unify our understanding of stem cell regulation at the cellular and molecular levels, and they are expected to advance efforts to control stem cells therapeutically. The present article reviews recent findings about cholinergic signaling that is essential to control stem cell function in a cholinergic niche.


2018 ◽  
Vol 20 (1) ◽  
Author(s):  
Safiah Olabi ◽  
Ahmet Ucar ◽  
Keith Brennan ◽  
Charles H. Streuli

Blood ◽  
2021 ◽  
Author(s):  
Yuqing Yang ◽  
Andrew J Kueh ◽  
Zoe Grant ◽  
Waruni Abeysekera ◽  
Alexandra L Garnham ◽  
...  

The histone acetyltransferase HBO1 (MYST2, KAT7) is indispensable for postgastrulation development, histone H3 lysine 14 acetylation (H3K14Ac) and the expression of embryonic patterning genes. In this study, we report the role of HBO1 in regulating hematopoietic stem cell function in adult hematopoiesis. We used two complementary cre-recombinase transgenes to conditionally delete Hbo1 (Mx1-Cre and Rosa26-CreERT2). Hbo1 null mice became moribund due to hematopoietic failure with pancytopenia in the blood and bone marrow two to six weeks after Hbo1 deletion. Hbo1 deleted bone marrow cells failed to repopulate hemoablated recipients in competitive transplantation experiments. Hbo1 deletion caused a rapid loss of hematopoietic progenitors (HPCs). The numbers of lineage-restricted progenitors for the erythroid, myeloid, B-and T-cell lineages were reduced. Loss of HBO1 resulted in an abnormally high rate of recruitment of quiescent hematopoietic stem cells (HSCs) into the cell cycle. Cycling HSCs produced progenitors at the expense of self-renewal, which led to the exhaustion of the HSC pool. Mechanistically, genes important for HSC functions were downregulated in HSC-enriched cell populations after Hbo1 deletion, including genes essential for HSC quiescence and self-renewal, such as Mpl, Tek(Tie-2), Gfi1b, Egr1, Tal1(Scl), Gata2, Erg, Pbx1, Meis1 and Hox9, as well as genes important for multipotent progenitor cells and lineage-specific progenitor cells, such as Gata1. HBO1 was required for H3K14Ac through the genome and particularly at gene loci required for HSC quiescence and self-renewal. Our data indicate that HBO1 promotes the expression of a transcription factor network essential for HSC maintenance and self-renewal in adult hematopoiesis.


2019 ◽  
Vol 20 (9) ◽  
pp. 2357 ◽  
Author(s):  
Eunmi Lee ◽  
Raziye Piranlioglu ◽  
Max S. Wicha ◽  
Hasan Korkaya

It is now widely believed that mammary epithelial cell plasticity, an important physiological process during the stages of mammary gland development, is exploited by the malignant cells for their successful disease progression. Normal mammary epithelial cells are heterogeneous and organized in hierarchical fashion, in which the mammary stem cells (MaSC) lie at the apex with regenerative capacity as well as plasticity. Despite the fact that the majority of studies supported the existence of multipotent MaSCs giving rise to both basal and luminal lineages, others proposed lineage restricted unipotent MaSCs. Consistent with the notion, the latest research has suggested that although normal MaSC subsets mainly stay in a quiescent state, they differ in their reconstituting ability, spatial localization, and molecular and epigenetic signatures in response to physiological stimuli within the respective microenvironment during the stages of mammary gland development. In this review, we will focus on current research on the biology of normal mammary stem cells with an emphasis on properties of cellular plasticity, self-renewal and quiescence, as well as the role of the microenvironment in regulating these processes. This will include a discussion of normal breast stem cell heterogeneity, stem cell markers, and lineage tracing studies.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1701-1701
Author(s):  
Leonie M. Kamminga ◽  
Kyrjon van Pelt ◽  
Bert Dontje ◽  
Gerald de Haan

Abstract Recently, several studies have suggested that the family of cyclin-dependent kinase inhibitors plays a crucial role in regulating hematopoietic stem and progenitor pool size. However, due to a lack of appropriate transplantation models, competitive repopulation assays have not been performed. In the present study we have backcrossed a p21 null allele from mice with a mixed genetic background to inbred C57BL/6 mice. As expected, mouse embryonic fibroblasts (MEFs) derived from B6p21−/− mice failed to undergo senescence, whereas B6p21+/+ MEFs show a normal senescent phenotype. Moreover, B6p21−/− CFU-GM were more resistant to radiation compared to B6p21+/+. In contrast, homozygous deletion of the p21 allele did not affect the percentage of Lin− Sca-1+ c-kit+ cells in S-phase when measured by 7-AAD staining, and did not result in any alterations of in vitro cobblestone area forming cell activity. In a competitive repopulating assay different ratios of Ly5.2 BM cells from B6p21−/− or B6p21+/+ littermates were competed with 2 x 106 Ly5.1 B6 BM cells. Assuming similar repopulating capacity of both cell populations, expected chimerism was calculated. Surprisingly, observed and expected chimerism were identical, strongly suggesting that B6p21−/− stem cells had completely normal competitive repopulating activity for up to 1 year after transplant. Our data argue against an important role of p21 in maintaining stem cell function during steady-state hematopoiesis.


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